Files
MaxScale/server/modules/protocol/mysql_backend.c
VilhoRaatikka 86a4c3ba90 Fix to #472, http://bugs.skysql.com/show_bug.cgi?id=472
Fix to #473, http://bugs.skysql.com/show_bug.cgi?id=473

Several memory issues. Read the code.
In general one-off hint is only added to gwbuf and freed in gwbuf_free. Stacked hint is copied to stack and to gwbuf. gwbuf is freed after routing but stacked hint is freed either in stop or when session is closed. All this applies to named hint as well except that in addition, it has one more copy in named hint struct which is emptied when session is closed.
2014-08-08 01:28:07 +03:00

1354 lines
53 KiB
C

/*
* This file is distributed as part of the SkySQL Gateway. It is free
* software: you can redistribute it and/or modify it under the terms of the
* GNU General Public License as published by the Free Software Foundation,
* version 2.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Copyright SkySQL Ab 2013
*/
#include "mysql_client_server_protocol.h"
#include <skygw_types.h>
#include <skygw_utils.h>
#include <log_manager.h>
/*
* MySQL Protocol module for handling the protocol between the gateway
* and the backend MySQL database.
*
* Revision History
* Date Who Description
* 14/06/2013 Mark Riddoch Initial version
* 17/06/2013 Massimiliano Pinto Added Gateway To Backends routines
* 27/06/2013 Vilho Raatikka Added skygw_log_write command as an example
* and necessary headers.
* 01/07/2013 Massimiliano Pinto Put Log Manager example code behind SS_DEBUG macros.
* 03/07/2013 Massimiliano Pinto Added delayq for incoming data before mysql connection
* 04/07/2013 Massimiliano Pinto Added asyncrhronous MySQL protocol connection to backend
* 05/07/2013 Massimiliano Pinto Added closeSession if backend auth fails
* 12/07/2013 Massimiliano Pinto Added Mysql Change User via dcb->func.auth()
* 15/07/2013 Massimiliano Pinto Added Mysql session change via dcb->func.session()
* 17/07/2013 Massimiliano Pinto Added dcb->command update from gwbuf->command for proper routing
server replies to client via router->clientReply
* 04/09/2013 Massimiliano Pinto Added dcb->session and dcb->session->client checks for NULL
* 12/09/2013 Massimiliano Pinto Added checks in gw_read_backend_event() for gw_read_backend_handshake
* 27/09/2013 Massimiliano Pinto Changed in gw_read_backend_event the check for dcb_read(), now is if rc < 0
*
*/
#include <modinfo.h>
MODULE_INFO info = {
MODULE_API_PROTOCOL,
MODULE_BETA_RELEASE,
GWPROTOCOL_VERSION,
"The MySQL to backend server protocol"
};
extern int lm_enabled_logfiles_bitmask;
static char *version_str = "V2.0.0";
static int gw_create_backend_connection(DCB *backend, SERVER *server, SESSION *in_session);
static int gw_read_backend_event(DCB* dcb);
static int gw_write_backend_event(DCB *dcb);
static int gw_MySQLWrite_backend(DCB *dcb, GWBUF *queue);
static int gw_error_backend_event(DCB *dcb);
static int gw_backend_close(DCB *dcb);
static int gw_backend_hangup(DCB *dcb);
static int backend_write_delayqueue(DCB *dcb);
static void backend_set_delayqueue(DCB *dcb, GWBUF *queue);
static int gw_change_user(DCB *backend_dcb, SERVER *server, SESSION *in_session, GWBUF *queue);
static GWBUF* process_response_data (DCB* dcb, GWBUF* readbuf, int nbytes_to_process);
#if defined(NOT_USED)
static int gw_session(DCB *backend_dcb, void *data);
#endif
static MYSQL_session* gw_get_shared_session_auth_info(DCB* dcb);
static GWPROTOCOL MyObject = {
gw_read_backend_event, /* Read - EPOLLIN handler */
gw_MySQLWrite_backend, /* Write - data from gateway */
gw_write_backend_event, /* WriteReady - EPOLLOUT handler */
gw_error_backend_event, /* Error - EPOLLERR handler */
gw_backend_hangup, /* HangUp - EPOLLHUP handler */
NULL, /* Accept */
gw_create_backend_connection, /* Connect */
gw_backend_close, /* Close */
NULL, /* Listen */
gw_change_user, /* Authentication */
NULL /* Session */
};
/*
* Implementation of the mandatory version entry point
*
* @return version string of the module
*/
char *
version()
{
return version_str;
}
/*
* The module initialisation routine, called when the module
* is first loaded.
*/
void
ModuleInit()
{
}
/*
* The module entry point routine. It is this routine that
* must populate the structure that is referred to as the
* "module object", this is a structure with the set of
* external entry points for this module.
*
* @return The module object
*/
GWPROTOCOL *
GetModuleObject()
{
return &MyObject;
}
static MYSQL_session* gw_get_shared_session_auth_info(
DCB* dcb)
{
MYSQL_session* auth_info = NULL;
CHK_DCB(dcb);
CHK_SESSION(dcb->session);
spinlock_acquire(&dcb->session->ses_lock);
if (dcb->session->state != SESSION_STATE_ALLOC) {
auth_info = dcb->session->data;
} else {
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"%lu [gw_get_shared_session_auth_info] Couldn't get "
"session authentication info. Session in a wrong state %d.",
pthread_self(),
dcb->session->state)));
}
spinlock_release(&dcb->session->ses_lock);
return auth_info;
}
/**
* Backend Read Event for EPOLLIN on the MySQL backend protocol module
* @param dcb The backend Descriptor Control Block
* @return 1 on operation, 0 for no action
*/
static int gw_read_backend_event(DCB *dcb) {
MySQLProtocol *client_protocol = NULL;
MySQLProtocol *backend_protocol = NULL;
MYSQL_session *current_session = NULL;
int rc = 0;
CHK_DCB(dcb);
CHK_SESSION(dcb->session);
/*< return only with complete session */
current_session = gw_get_shared_session_auth_info(dcb);
ss_dassert(current_session != NULL);
backend_protocol = (MySQLProtocol *) dcb->protocol;
CHK_PROTOCOL(backend_protocol);
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_read_backend_event] Read dcb %p fd %d protocol "
"state %d, %s.",
pthread_self(),
dcb,
dcb->fd,
backend_protocol->protocol_auth_state,
STRPROTOCOLSTATE(backend_protocol->protocol_auth_state))));
/* backend is connected:
*
* 1. read server handshake
* 2. if (success) write auth request
* 3. and return
*/
/*<
* If starting to auhenticate with backend server, lock dcb
* to prevent overlapping processing of auth messages.
*/
if (backend_protocol->protocol_auth_state == MYSQL_CONNECTED)
{
spinlock_acquire(&dcb->authlock);
backend_protocol = (MySQLProtocol *) dcb->protocol;
CHK_PROTOCOL(backend_protocol);
if (backend_protocol->protocol_auth_state == MYSQL_CONNECTED)
{
if (gw_read_backend_handshake(backend_protocol) != 0)
{
backend_protocol->protocol_auth_state = MYSQL_AUTH_FAILED;
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_read_backend_event] after "
"gw_read_backend_handshake, fd %d, "
"state = MYSQL_AUTH_FAILED.",
pthread_self(),
backend_protocol->owner_dcb->fd)));
}
else
{
/* handshake decoded, send the auth credentials */
if (gw_send_authentication_to_backend(
current_session->db,
current_session->user,
current_session->client_sha1,
backend_protocol) != 0)
{
backend_protocol->protocol_auth_state = MYSQL_AUTH_FAILED;
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_read_backend_event] after "
"gw_send_authentication_to_backend "
"fd %d, state = MYSQL_AUTH_FAILED.",
pthread_self(),
backend_protocol->owner_dcb->fd)));
}
else
{
backend_protocol->protocol_auth_state = MYSQL_AUTH_RECV;
}
}
}
spinlock_release(&dcb->authlock);
}
/*
* Now:
* -- check the authentication reply from backend
* OR
* -- handle a previous handshake error
*/
if (backend_protocol->protocol_auth_state == MYSQL_AUTH_RECV ||
backend_protocol->protocol_auth_state == MYSQL_AUTH_FAILED)
{
spinlock_acquire(&dcb->authlock);
backend_protocol = (MySQLProtocol *) dcb->protocol;
CHK_PROTOCOL(backend_protocol);
if (backend_protocol->protocol_auth_state == MYSQL_AUTH_RECV ||
backend_protocol->protocol_auth_state == MYSQL_AUTH_FAILED)
{
ROUTER_OBJECT *router = NULL;
ROUTER *router_instance = NULL;
void *rsession = NULL;
SESSION *session = dcb->session;
int receive_rc = 0;
CHK_SESSION(session);
router = session->service->router;
router_instance = session->service->router_instance;
rsession = session->router_session;
if (backend_protocol->protocol_auth_state == MYSQL_AUTH_RECV) {
/*<
* Read backed auth reply
*/
receive_rc =
gw_receive_backend_auth(backend_protocol);
switch (receive_rc) {
case -1:
backend_protocol->protocol_auth_state = MYSQL_AUTH_FAILED;
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_read_backend_event] after "
"gw_receive_backend_authentication "
"fd %d, state = MYSQL_AUTH_FAILED.",
pthread_self(),
backend_protocol->owner_dcb->fd)));
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Error : Backend server didn't "
"accept authentication for user "
"%s.",
current_session->user)));
break;
case 1:
backend_protocol->protocol_auth_state = MYSQL_IDLE;
LOGIF(LD, (skygw_log_write_flush(
LOGFILE_DEBUG,
"%lu [gw_read_backend_event] "
"gw_receive_backend_auth succeed. "
"dcb %p fd %d, user %s.",
pthread_self(),
dcb,
dcb->fd,
current_session->user)));
break;
default:
ss_dassert(receive_rc == 0);
LOGIF(LD, (skygw_log_write_flush(
LOGFILE_DEBUG,
"%lu [gw_read_backend_event] "
"gw_receive_backend_auth read "
"successfully "
"nothing. dcb %p fd %d, user %s.",
pthread_self(),
dcb,
dcb->fd,
current_session->user)));
rc = 0;
goto return_with_lock;
break;
} /* switch */
}
if (backend_protocol->protocol_auth_state == MYSQL_AUTH_FAILED)
{
/**
* protocol state won't change anymore,
* lock can be freed
*/
spinlock_release(&dcb->authlock);
spinlock_acquire(&dcb->delayqlock);
if (dcb->delayq != NULL)
{
while ((dcb->delayq = gwbuf_consume(
dcb->delayq,
GWBUF_LENGTH(dcb->delayq))) != NULL);
}
spinlock_release(&dcb->delayqlock);
{
GWBUF* errbuf;
bool succp;
/* try reload users' table for next connection */
service_refresh_users(dcb->session->service);
#if defined(SS_DEBUG)
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_read_backend_event] "
"calling handleError. Backend "
"DCB %p, session %p",
pthread_self(),
dcb,
dcb->session)));
#endif
errbuf = mysql_create_custom_error(
1,
0,
"Authentication with backend failed. "
"Session will be closed.");
router->handleError(router_instance,
rsession,
errbuf,
dcb,
ERRACT_REPLY_CLIENT,
&succp);
ss_dassert(!succp);
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_read_backend_event] "
"after calling handleError. Backend "
"DCB %p, session %p",
pthread_self(),
dcb,
dcb->session)));
if (session != NULL)
{
spinlock_acquire(&session->ses_lock);
session->state = SESSION_STATE_STOPPING;
spinlock_release(&session->ses_lock);
}
dcb_close(dcb);
}
rc = 1;
goto return_rc;
}
else
{
ss_dassert(backend_protocol->protocol_auth_state == MYSQL_IDLE);
LOGIF(LD, (skygw_log_write_flush(
LOGFILE_DEBUG,
"%lu [gw_read_backend_event] "
"gw_receive_backend_auth succeed. Fd %d, "
"user %s.",
pthread_self(),
dcb->fd,
current_session->user)));
/* check the delay queue and flush the data */
if (dcb->delayq)
{
rc = backend_write_delayqueue(dcb);
goto return_with_lock;
}
}
} /* MYSQL_AUTH_RECV || MYSQL_AUTH_FAILED */
spinlock_release(&dcb->authlock);
} /* MYSQL_AUTH_RECV || MYSQL_AUTH_FAILED */
/* reading MySQL command output from backend and writing to the client */
{
GWBUF *read_buffer = NULL;
ROUTER_OBJECT *router = NULL;
ROUTER *router_instance = NULL;
SESSION *session = dcb->session;
int nbytes_read = 0;
CHK_SESSION(session);
router = session->service->router;
router_instance = session->service->router_instance;
/* read available backend data */
rc = dcb_read(dcb, &read_buffer);
if (rc < 0)
{
GWBUF* errbuf;
bool succp;
#if defined(SS_DEBUG)
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Backend read error handling #2.")));
#endif
errbuf = mysql_create_custom_error(
1,
0,
"Read from backend failed");
router->handleError(router_instance,
session->router_session,
errbuf,
dcb,
ERRACT_NEW_CONNECTION,
&succp);
if (!succp)
{
spinlock_acquire(&session->ses_lock);
session->state = SESSION_STATE_STOPPING;
spinlock_release(&session->ses_lock);
}
dcb_close(dcb);
rc = 0;
goto return_rc;
}
nbytes_read = gwbuf_length(read_buffer);
if (nbytes_read == 0)
{
goto return_rc;
}
else
{
ss_dassert(read_buffer != NULL);
}
/** Packet prefix was read earlier */
if (dcb->dcb_readqueue)
{
read_buffer = gwbuf_append(dcb->dcb_readqueue, read_buffer);
nbytes_read = gwbuf_length(read_buffer);
if (nbytes_read < 5) /*< read at least command type */
{
rc = 0;
goto return_rc;
}
/** There is at least length and command type. */
else
{
read_buffer = dcb->dcb_readqueue;
dcb->dcb_readqueue = NULL;
}
}
else
{
if (nbytes_read < 5)
{
gwbuf_append(dcb->dcb_readqueue, read_buffer);
rc = 0;
goto return_rc;
}
}
/**
* If protocol has session command set, concatenate whole
* response into one buffer.
*/
if (protocol_get_srv_command((MySQLProtocol *)dcb->protocol, false) !=
MYSQL_COM_UNDEFINED)
{
read_buffer = process_response_data(dcb, read_buffer, nbytes_read);
}
/*<
* If dcb->session->client is freed already it may be NULL.
*/
if (dcb->session->client != NULL)
{
client_protocol = SESSION_PROTOCOL(dcb->session,
MySQLProtocol);
if (client_protocol != NULL)
{
CHK_PROTOCOL(client_protocol);
if (client_protocol->protocol_auth_state ==
MYSQL_IDLE)
{
gwbuf_set_type(read_buffer, GWBUF_TYPE_MYSQL);
router->clientReply(
router_instance,
session->router_session,
read_buffer,
dcb);
rc = 1;
}
goto return_rc;
}
else if (dcb->session->client->dcb_role == DCB_ROLE_INTERNAL)
{
gwbuf_set_type(read_buffer, GWBUF_TYPE_MYSQL);
router->clientReply(router_instance, session->router_session, read_buffer, dcb);
rc = 1;
}
}
}
return_rc:
return rc;
return_with_lock:
spinlock_release(&dcb->authlock);
goto return_rc;
}
/*
* EPOLLOUT handler for the MySQL Backend protocol module.
*
* @param dcb The descriptor control block
* @return 1 in success, 0 in case of failure,
*/
static int gw_write_backend_event(DCB *dcb) {
int rc = 0;
MySQLProtocol *backend_protocol = dcb->protocol;
/*<
* Don't write to backend if backend_dcb is not in poll set anymore.
*/
if (dcb->state != DCB_STATE_POLLING) {
uint8_t* data;
if (dcb->writeq != NULL)
{
data = (uint8_t *)GWBUF_DATA(dcb->writeq);
if (!(MYSQL_IS_COM_QUIT(data)))
{
/*< vraa : errorHandle */
mysql_send_custom_error(
dcb->session->client,
1,
0,
"Writing to backend failed due invalid Maxscale "
"state.");
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_write_backend_event] Write to backend "
"dcb %p fd %d "
"failed due invalid state %s.",
pthread_self(),
dcb,
dcb->fd,
STRDCBSTATE(dcb->state))));
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Error : Attempt to write buffered data to backend "
"failed "
"due internal inconsistent state.")));
rc = 0;
}
}
else
{
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_write_backend_event] Dcb %p in state %s "
"but there's nothing to write either.",
pthread_self(),
dcb,
STRDCBSTATE(dcb->state))));
rc = 1;
}
goto return_rc;
}
if (backend_protocol->protocol_auth_state == MYSQL_PENDING_CONNECT) {
backend_protocol->protocol_auth_state = MYSQL_CONNECTED;
rc = 1;
goto return_rc;
}
dcb_drain_writeq(dcb);
rc = 1;
return_rc:
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_write_backend_event] "
"wrote to dcb %p fd %d, return %d",
pthread_self(),
dcb,
dcb->fd,
rc)));
return rc;
}
/*
* Write function for backend DCB. Store command to protocol.
*
* @param dcb The DCB of the backend
* @param queue Queue of buffers to write
* @return 0 on failure, 1 on success
*/
static int
gw_MySQLWrite_backend(DCB *dcb, GWBUF *queue)
{
MySQLProtocol *backend_protocol = dcb->protocol;
int rc = 0;
spinlock_acquire(&dcb->authlock);
/**
* Pick action according to state of protocol.
* If auth failed, return value is 0, write and buffered write
* return 1.
*/
switch (backend_protocol->protocol_auth_state) {
case MYSQL_AUTH_FAILED:
{
size_t len;
char* str;
uint8_t* packet = (uint8_t *)queue->start;
uint8_t* startpoint;
len = (size_t)MYSQL_GET_PACKET_LEN(packet);
startpoint = &packet[5];
str = (char *)malloc(len+1);
snprintf(str, len+1, "%s", startpoint);
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Error : Unable to write to backend due to "
"authentication failure.")));
/** Consume query buffer */
while ((queue = gwbuf_consume(
queue,
GWBUF_LENGTH(queue))) != NULL);
free(str);
rc = 0;
spinlock_release(&dcb->authlock);
goto return_rc;
break;
}
case MYSQL_IDLE:
{
uint8_t* ptr = GWBUF_DATA(queue);
int cmd = MYSQL_GET_COMMAND(ptr);
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_MySQLWrite_backend] write to dcb %p "
"fd %d protocol state %s.",
pthread_self(),
dcb,
dcb->fd,
STRPROTOCOLSTATE(backend_protocol->protocol_auth_state))));
spinlock_release(&dcb->authlock);
/**
* Statement type is used in readwrite split router.
* Command is *not* set for readconn router.
*
* Server commands are stored to MySQLProtocol structure
* if buffer always includes a single statement.
*/
if (GWBUF_IS_TYPE_SINGLE_STMT(queue) &&
GWBUF_IS_TYPE_SESCMD(queue))
{
/** Record the command to backend's protocol */
protocol_add_srv_command(backend_protocol, cmd);
}
/** Write to backend */
rc = dcb_write(dcb, queue);
goto return_rc;
break;
}
default:
{
uint8_t* ptr = GWBUF_DATA(queue);
int cmd = MYSQL_GET_COMMAND(ptr);
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_MySQLWrite_backend] delayed write to "
"dcb %p fd %d protocol state %s.",
pthread_self(),
dcb,
dcb->fd,
STRPROTOCOLSTATE(backend_protocol->protocol_auth_state))));
/**
* In case of session commands, store command to DCB's
* protocol struct.
*/
if (GWBUF_IS_TYPE_SINGLE_STMT(queue) &&
GWBUF_IS_TYPE_SESCMD(queue))
{
/** Record the command to backend's protocol */
protocol_add_srv_command(backend_protocol, cmd);
}
/*<
* Now put the incoming data to the delay queue unless backend is
* connected with auth ok
*/
backend_set_delayqueue(dcb, queue);
spinlock_release(&dcb->authlock);
rc = 1;
goto return_rc;
break;
}
}
return_rc:
return rc;
}
/**
* Error event handler.
* Create error message, pass it to router's error handler and if error
* handler fails in providing enough backend servers, mark session being
* closed and call DCB close function which triggers closing router session
* and related backends (if any exists.
*/
static int gw_error_backend_event(DCB *dcb)
{
SESSION* session;
void* rsession;
ROUTER_OBJECT* router;
ROUTER* router_instance;
GWBUF* errbuf;
bool succp;
CHK_DCB(dcb);
session = dcb->session;
CHK_SESSION(session);
rsession = session->router_session;
router = session->service->router;
router_instance = session->service->router_instance;
#if defined(SS_DEBUG)
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Backend error event handling.")));
#endif
/**
* Avoid running redundant error handling procedure.
* dcb_close is already called for the DCB. Thus, either connection is
* closed by router and COM_QUIT sent or there was an error which
* have already been handled.
*/
if (dcb->state != DCB_STATE_POLLING)
{
return 1;
}
errbuf = mysql_create_custom_error(
1,
0,
"Lost connection to backend server.");
router->handleError(router_instance,
rsession,
errbuf,
dcb,
ERRACT_NEW_CONNECTION,
&succp);
/** There are not required backends available, close session. */
if (!succp) {
spinlock_acquire(&session->ses_lock);
session->state = SESSION_STATE_STOPPING;
spinlock_release(&session->ses_lock);
}
dcb_close(dcb);
return 1;
}
/*
* Create a new backend connection.
*
* This routine will connect to a backend server and it is called by dbc_connect
* in router->newSession
*
* @param backend_dcb, in, out, use - backend DCB allocated from dcb_connect
* @param server, in, use - server to connect to
* @param session, in use - current session from client DCB
* @return 0/1 on Success and -1 on Failure.
* If succesful, returns positive fd to socket which is connected to
* backend server. Positive fd is copied to protocol and to dcb.
* If fails, fd == -1 and socket is closed.
*/
static int gw_create_backend_connection(
DCB *backend_dcb,
SERVER *server,
SESSION *session)
{
MySQLProtocol *protocol = NULL;
int rv = -1;
int fd = -1;
protocol = mysql_protocol_init(backend_dcb, -1);
ss_dassert(protocol != NULL);
if (protocol == NULL) {
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_create_backend_connection] Failed to create "
"protocol object for backend connection.",
pthread_self())));
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Error: Failed to create "
"protocol object for backend connection.")));
goto return_fd;
}
/*< if succeed, fd > 0, -1 otherwise */
rv = gw_do_connect_to_backend(server->name, server->port, &fd);
/*< Assign protocol with backend_dcb */
backend_dcb->protocol = protocol;
/*< Set protocol state */
switch (rv) {
case 0:
ss_dassert(fd > 0);
protocol->fd = fd;
protocol->protocol_auth_state = MYSQL_CONNECTED;
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_create_backend_connection] Established "
"connection to %s:%i, protocol fd %d client "
"fd %d.",
pthread_self(),
server->name,
server->port,
protocol->fd,
session->client->fd)));
break;
case 1:
ss_dassert(fd > 0);
protocol->protocol_auth_state = MYSQL_PENDING_CONNECT;
protocol->fd = fd;
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_create_backend_connection] Connection "
"pending to %s:%i, protocol fd %d client fd %d.",
pthread_self(),
server->name,
server->port,
protocol->fd,
session->client->fd)));
break;
default:
ss_dassert(fd == -1);
ss_dassert(protocol->protocol_auth_state == MYSQL_ALLOC);
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_create_backend_connection] Connection "
"failed to %s:%i, protocol fd %d client fd %d.",
pthread_self(),
server->name,
server->port,
protocol->fd,
session->client->fd)));
break;
} /*< switch */
return_fd:
return fd;
}
/**
* Error event handler.
* Create error message, pass it to router's error handler and if error
* handler fails in providing enough backend servers, mark session being
* closed and call DCB close function which triggers closing router session
* and related backends (if any exists.
*
* @param dcb The current Backend DCB
* @return 1 always
*/
static int
gw_backend_hangup(DCB *dcb)
{
SESSION* session;
void* rsession;
ROUTER_OBJECT* router;
ROUTER* router_instance;
bool succp;
GWBUF* errbuf;
CHK_DCB(dcb);
session = dcb->session;
CHK_SESSION(session);
rsession = session->router_session;
router = session->service->router;
router_instance = session->service->router_instance;
#if defined(SS_DEBUG)
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Backend hangup error handling.")));
#endif
errbuf = mysql_create_custom_error(
1,
0,
"Lost connection to backend server.");
router->handleError(router_instance,
rsession,
errbuf,
dcb,
ERRACT_NEW_CONNECTION,
&succp);
/** There are not required backends available, close session. */
if (!succp) {
#if defined(SS_DEBUG)
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Backend hangup -> closing session.")));
#endif
spinlock_acquire(&session->ses_lock);
session->state = SESSION_STATE_STOPPING;
spinlock_release(&session->ses_lock);
}
dcb_close(dcb);
return 1;
}
/**
* Send COM_QUIT to backend so that it can be closed.
* @param dcb The current Backend DCB
* @return 1 always
*/
static int
gw_backend_close(DCB *dcb)
{
DCB* client_dcb;
SESSION* session;
GWBUF* quitbuf;
CHK_DCB(dcb);
session = dcb->session;
CHK_SESSION(session);
quitbuf = mysql_create_com_quit(NULL, 0);
gwbuf_set_type(quitbuf, GWBUF_TYPE_MYSQL);
/** Send COM_QUIT to the backend being closed */
mysql_send_com_quit(dcb, 0, quitbuf);
mysql_protocol_done(dcb);
if (session != NULL && session->state == SESSION_STATE_STOPPING)
{
client_dcb = session->client;
if (client_dcb != NULL &&
client_dcb->state == DCB_STATE_POLLING)
{
/** Close client DCB */
dcb_close(client_dcb);
}
}
return 1;
}
/**
* This routine put into the delay queue the input queue
* The input is what backend DCB is receiving
* The routine is called from func.write() when mysql backend connection
* is not yet complete buu there are inout data from client
*
* @param dcb The current backend DCB
* @param queue Input data in the GWBUF struct
*/
static void backend_set_delayqueue(DCB *dcb, GWBUF *queue) {
spinlock_acquire(&dcb->delayqlock);
if (dcb->delayq) {
/* Append data */
dcb->delayq = gwbuf_append(dcb->delayq, queue);
} else {
if (queue != NULL) {
/* create the delay queue */
dcb->delayq = queue;
}
}
spinlock_release(&dcb->delayqlock);
}
/**
* This routine writes the delayq via dcb_write
* The dcb->delayq contains data received from the client before
* mysql backend authentication succeded
*
* @param dcb The current backend DCB
* @return The dcb_write status
*/
static int backend_write_delayqueue(DCB *dcb)
{
GWBUF *localq = NULL;
int rc;
spinlock_acquire(&dcb->delayqlock);
if (dcb->delayq == NULL)
{
spinlock_release(&dcb->delayqlock);
rc = 1;
}
else
{
localq = dcb->delayq;
dcb->delayq = NULL;
spinlock_release(&dcb->delayqlock);
rc = dcb_write(dcb, localq);
}
if (rc == 0)
{
GWBUF* errbuf;
bool succp;
ROUTER_OBJECT *router = NULL;
ROUTER *router_instance = NULL;
void *rsession = NULL;
SESSION *session = dcb->session;
CHK_SESSION(session);
router = session->service->router;
router_instance = session->service->router_instance;
rsession = session->router_session;
#if defined(SS_DEBUG)
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Backend write delayqueue error handling.")));
#endif
errbuf = mysql_create_custom_error(
1,
0,
"Failed to write buffered data to back-end server. "
"Buffer was empty or back-end was disconnected during "
"operation. Session will be closed.");
router->handleError(router_instance,
rsession,
errbuf,
dcb,
ERRACT_NEW_CONNECTION,
&succp);
if (!succp)
{
if (session != NULL)
{
spinlock_acquire(&session->ses_lock);
session->state = SESSION_STATE_STOPPING;
spinlock_release(&session->ses_lock);
}
dcb_close(dcb);
}
}
return rc;
}
static int gw_change_user(
DCB *backend,
SERVER *server,
SESSION *in_session,
GWBUF *queue)
{
MYSQL_session *current_session = NULL;
MySQLProtocol *backend_protocol = NULL;
MySQLProtocol *client_protocol = NULL;
char username[MYSQL_USER_MAXLEN+1]="";
char database[MYSQL_DATABASE_MAXLEN+1]="";
uint8_t client_sha1[MYSQL_SCRAMBLE_LEN]="";
uint8_t *client_auth_packet = GWBUF_DATA(queue);
unsigned int auth_token_len = 0;
uint8_t *auth_token = NULL;
int rv = -1;
int auth_ret = 1;
current_session = (MYSQL_session *)in_session->client->data;
backend_protocol = backend->protocol;
client_protocol = in_session->client->protocol;
// now get the user, after 4 bytes header and 1 byte command
client_auth_packet += 5;
strcpy(username, (char *)client_auth_packet);
client_auth_packet += strlen(username) + 1;
// get the auth token len
memcpy(&auth_token_len, client_auth_packet, 1);
ss_dassert(auth_token_len >= 0);
client_auth_packet++;
// allocate memory for token only if auth_token_len > 0
if (auth_token_len > 0) {
auth_token = (uint8_t *)malloc(auth_token_len);
ss_dassert(auth_token != NULL);
if (auth_token == NULL)
return rv;
memcpy(auth_token, client_auth_packet, auth_token_len);
client_auth_packet += auth_token_len;
}
// decode the token and check the password
// Note: if auth_token_len == 0 && auth_token == NULL, user is without password
auth_ret = gw_check_mysql_scramble_data(backend->session->client, auth_token, auth_token_len, client_protocol->scramble, sizeof(client_protocol->scramble), username, client_sha1);
if (auth_ret != 0) {
if (!service_refresh_users(backend->session->client->service)) {
/* Try authentication again with new repository data */
/* Note: if no auth client authentication will fail */
auth_ret = gw_check_mysql_scramble_data(backend->session->client, auth_token, auth_token_len, client_protocol->scramble, sizeof(client_protocol->scramble), username, client_sha1);
}
}
// let's free the auth_token now
if (auth_token)
free(auth_token);
if (auth_ret != 0) {
/*< vraa : errorHandle */
// send the error packet
mysql_send_auth_error(backend->session->client, 1, 0, "Authorization failed on change_user");
rv = 1;
} else {
// get db name
strcpy(database, (char *)client_auth_packet);
rv = gw_send_change_user_to_backend(database, username, client_sha1, backend_protocol);
/*<
* Now copy new data into user session
*/
strcpy(current_session->user, username);
strcpy(current_session->db, database);
memcpy(current_session->client_sha1, client_sha1, sizeof(current_session->client_sha1));
}
gwbuf_free(queue);
return rv;
}
/**
* Session Change wrapper for func.write
* The reply packet will be back routed to the right server
* in the gw_read_backend_event checking the ROUTER_CHANGE_SESSION command in dcb->command
*
* @param
* @return always 1
*/
/*
static int gw_session(DCB *backend_dcb, void *data) {
GWBUF *queue = NULL;
queue = (GWBUF *) data;
backend_dcb->func.write(backend_dcb, queue);
return 1;
}
*/
/**
* Move packets or parts of packets from redbuf to outbuf as the packet headers
* and lengths have been noticed and counted.
* Session commands need to be marked so that they can be handled properly in
* the router's clientReply.
* Return the pointer to outbuf.
*/
static GWBUF* process_response_data (
DCB* dcb,
GWBUF* readbuf,
int nbytes_to_process) /*< number of new bytes read */
{
int npackets_left = 0; /*< response's packet count */
size_t nbytes_left = 0; /*< nbytes to be read for the packet */
MySQLProtocol* p;
GWBUF* outbuf = NULL;
/** Get command which was stored in gw_MySQLWrite_backend */
p = DCB_PROTOCOL(dcb, MySQLProtocol);
CHK_PROTOCOL(p);
/** All buffers processed here are sescmd responses */
gwbuf_set_type(readbuf, GWBUF_TYPE_SESCMD_RESPONSE);
/**
* Now it is known how many packets there should be and how much
* is read earlier.
*/
while (nbytes_to_process != 0)
{
mysql_server_cmd_t srvcmd;
bool succp;
srvcmd = protocol_get_srv_command(p, false);
/**
* Read values from protocol structure, fails if values are
* uninitialized.
*/
if (npackets_left == 0)
{
succp = protocol_get_response_status(p, &npackets_left, &nbytes_left);
if (!succp || npackets_left == 0)
{
/**
* Examine command type and the readbuf. Conclude response
* packet count from the command type or from the first
* packet content. Fails if read buffer doesn't include
* enough data to read the packet length.
*/
init_response_status(readbuf, srvcmd, &npackets_left, &nbytes_left);
}
}
/** Only session commands with responses should be processed */
ss_dassert(npackets_left > 0);
/** Read incomplete packet. */
if (nbytes_left > nbytes_to_process)
{
/** Includes length info so it can be processed */
if (nbytes_to_process >= 5)
{
/** discard source buffer */
readbuf = gwbuf_consume(readbuf, GWBUF_LENGTH(readbuf));
nbytes_left -= nbytes_to_process;
}
nbytes_to_process = 0;
}
/** Packet was read. All bytes belonged to the last packet. */
else if (nbytes_left == nbytes_to_process)
{
nbytes_left = 0;
nbytes_to_process = 0;
ss_dassert(npackets_left > 0);
npackets_left -= 1;
outbuf = gwbuf_append(outbuf, readbuf);
readbuf = NULL;
}
/**
* Packet was read. There should be more since bytes were
* left over.
* Move the next packet to its own buffer and add that next
* to the prev packet's buffer.
*/
else /*< nbytes_left < nbytes_to_process */
{
nbytes_to_process -= nbytes_left;
/** Move the prefix of the buffer to outbuf from redbuf */
outbuf = gwbuf_append(outbuf, gwbuf_clone_portion(readbuf, 0, nbytes_left));
readbuf = gwbuf_consume(readbuf, nbytes_left);
ss_dassert(npackets_left > 0);
npackets_left -= 1;
nbytes_left = 0;
}
/** Store new status to protocol structure */
protocol_set_response_status(p, npackets_left, nbytes_left);
/** A complete packet was read */
if (nbytes_left == 0)
{
/** No more packets in this response */
if (npackets_left == 0)
{
GWBUF* b = outbuf;
while (b->next != NULL)
{
b = b->next;
}
/** Mark last as end of response */
gwbuf_set_type(b, GWBUF_TYPE_RESPONSE_END);
/** Archive the command */
protocol_archive_srv_command(p);
}
/** Read next packet */
else
{
uint8_t* data;
/** Read next packet length */
data = GWBUF_DATA(readbuf);
nbytes_left = MYSQL_GET_PACKET_LEN(data)+MYSQL_HEADER_LEN;
/** Store new status to protocol structure */
protocol_set_response_status(p, npackets_left, nbytes_left);
}
}
}
return outbuf;
}